Exterior Lighting

Exterior Lighting

NOTE: The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).

The exterior lighting system consists of the following components:

- Headlamp assemblies
- Ballasts (located on the underside of each headlamp)
- Fog lamps
- Supplemental mirror turn signal lamps (located in the exterior mirrors)
- Rear lamp assemblies
- Liftgate lamp
- High mounted stoplamp
- Reversing lamp
- Headlamp switch
- Multifunction switch
- Hazard flasher lamp switch (located near the climate controls and integrated into the Front Controls Interface Module (FCIM))
- Light sensor
- Stoplamp switch
- Headlamp Control Module (HCM) (located at the front of the frame rail below the LH headlamp assembly)
- Headlamp Control Module 2 (HCM-2) (located next to the interior mirror)
- SJB (located left of the brake pedal assembly)

Battery Saver

NOTE: Time-out is 1 minute if the vehicle has less than 80 km (50 miles).

The battery saver is internal to the SJB and provides automatic shut-off of the headlamps and parking lamps after 10 minutes in order to save battery voltage. A timer is started when the ignition switch is turned to the OFF position with the headlamp switch in the HEADLAMPS ON position, or the headlamp switch is placed in the HEADLAMPS ON position with the ignition switch off. When the time-out period has elapsed, the voltage is automatically shut off to the lamps by the battery saver.

The battery saver does not control the parking lamps if the headlamp switch is in the PARKING LAMPS ON position.

Lamp Assembly Condensation

Exterior lamps are vented to accommodate normal changes in pressure. Condensation can be a natural by-product of this design. When moist air enters the lamp assembly through the vents, there is a possibility that condensation can occur if the temperature is cold. When normal condensation occurs, a thin film of mist can form on the interior of the lens. The thin mist eventually clears and exits through the vents during normal operation. Time to clear the lens of acceptable mist varies with ambient humidity and lamp types. Normal condensation clears from any lamp in 48 hours under dry conditions.

Do not replace a lamp assembly with acceptable levels of condensation such as:

- presence of thin mist (no streaks, drip marks or droplets are present)
- fine mist covers less than 50% of the lens

Examples of unacceptable moisture (usually caused by a lamp housing leak):

- water puddling inside the lamp
- large water droplets, drip marks or streaks present on the interior of the lens

Headlamps

The headlamp system is a dual-beam pattern system. It consists of a ballast, a High Intensity Discharge (HID) bulb and a shutter within each headlamp.

When the low beams are requested (based on inputs to the SJB), the HID ballasts energize and provide high voltage to the HID bulbs.

When the high beams are requested, the HID ballasts remain powered and a shutter within each headlamp is activated. This changes the headlamp beam pattern to illuminate a greater distance.

Flash-To-Pass

If the low beams are off when the flash-to-pass is requested, the HID ballasts and the shutters within the headlamps are activated for approximately 0.5 second. If the low beams are on when the flash-to-pass is requested, the shutters within the headlamps are activated for as long as the multifunction switch is held in the FLASH-TO-PASS position.

Autolamps

The autolamp system provides light sensitive automatic on/off control of the exterior lamps. The autolamp system keeps the exterior lamps on for a pre-selected period of time after the ignition switch is turned to the OFF position (20 seconds is the factory default setting). The pre-selected time lapse is adjustable up to approximately 3 minutes.

Headlamps On With Wipers On Feature

If the headlamp switch is in the AUTOLAMPS ON position and the front wipers are on for more than 3 seconds (except during a mist wipe or while the wipers are on to clear washer fluid during a wash condition), the exterior lamps are turned on. The exterior lamps are turned off when the ignition switch is changed to the OFF or ACC position, the headlamp switch is placed in the OFF position, or the front wipers are off for more than 30 seconds. The exception to this is when the exterior lights are on because of darkness determined by the light sensor.

Refer to Wipers and Washers Testing and Inspection for diagnostics of the headlamps on with wipers on feature.

Stoplamps

The stoplamp switch is located on the brake pedal assembly. The stoplamps are supplied voltage when the brake pedal is applied. The vehicle is equipped with LED stoplamps.

Turn Signal/Hazard Lamps

The front turn signal lamps are located within the headlamp assemblies and the supplemental mirror turn signal lamps are located within the exterior mirrors. The rear turn lamps share functionality with the stoplamps. When the multifunction switch is placed in the LH or RH TURN positions, the SJB routes voltage to the LH or RH turn signal lamps. The SJB then cycles the voltage on and off approximately 80 times per minute. If a front turn bulb is inoperative, the SJB cycles the voltage on and off approximately 160 times per minute.

The hazard switch is located near the climate controls in the center of the instrument panel. When the hazard switch is pressed, the SJB supplies voltage to all the turn lamps. The SJB cycles the voltage on and off approximately 80 times per minute.

Parking Lamps

The SJB supplies voltage to the parking lamps when demanded. All of the parking lamps are LED except for the license plate lamps which are incandescent. The parking lamp system includes the following:

- Front parking/side marker lamps (integrated into the headlamp assemblies)
- Rear parking lamps (including the liftgate lamp)
- License plate lamps

Fog Lamps

The fog lamp switch is integrated into the headlamp switch. When the fog lamp switch is engaged, the SJB provides ground for the fog lamp relay coil (integrated into the SJB), which then energizes and routes voltage to the fog lamps. The fog lamps can be turned on when the ignition switch is in the RUN or ACC position, the parking lamps are on, and the high beam headlamps are off.

Reversing Lamps

When the transmission is placed in REVERSE (R), the reversing lamp relay provides voltage to the reversing lamps. The reversing lamp is located in the center of the liftgate lamp which also houses the LED parking lamps that run the width of the liftgate.

Trailer Tow

When the vehicle's rear stop/turn or parking lamps are illuminated, voltage is also supplied to a corresponding trailer tow relay (coil side) located in the Battery Junction Box (BJB).

Daytime Running Lamps (DRL)

The Daytime Running Lamps (DRL) system operates the fog lamps at full intensity by energizing the fog lamp relay.

The DRL turn on when the following conditions are met:

- The ignition switch is in the RUN position.
- The headlamps have not been turned on by the autolamp system or the headlamp switch.
- The transmission is not in PARK (P).

The SJB can be configured to turn the DRL on for this vehicle. Refer to Module Configuration Testing and Inspection for additional information on this programmable parameter.